1. Field of the Invention
The invention most generally relates to measuring devices which will measure linear and angular measurements and which devices are useful for the layout of typically construction items which require repeatable accuracy of dimensions and repeatable location of points lines and planes relative to reference points, lines and planes. More particularly, the present invention provides a novel means for pivotably and adjustably connecting a pair of protractor members which may be used primarily within the field of construction.
This invention relates to improvements in geometrical instruments, having for an object to provide a combined straight edge, measuring device and adjustable angle, especially advantageous for use in the measuring of lumber or other material and "laying out" thereon markings which are indicative of the proper measurements and angles at which such material is to be cut.
This invention further relates to improvements in stair and roofing squares, and has particular reference to a device for determining the proper cutting angle for laying out rafters, stairs, hoppers and other angular cuts. The device may also be used for constructing hips or valleys as well as ridges of roofs of buildings.
The invention provides an indispensable device which will occupy a minimum amount of space in a tool box, a device that is economical to manufacture, and one that is easy to use.
2. Description of the Prior Art
None of the known previous related inventions presently provide for the novel and unobvious combination of pivotably connected protractor ends, an extendible central connecting member, edge-guide pins and means for clamping in place the various components so as to form a device capable of easily and rapidly determining stair tread and riser angles or roofing rafter angles and many other construction and lay-out problems and to scribe prior to cutting the lumber.
As indicated above, presently there is nothing available that provides for the pivotably adjustable protractor ends. It would be advantageous to have an improved versatile measuring device device which would be easy to use, simple and reliable. It would also be advantageous to have an extendible connecting member which is capable of forming different sizes and which could be used to create various angles particularly between the protractor members of the measuring device.
Some inventions related to the instant invention and disclosed in the following United States Patents have been studied. The following is a brief description and discussion of patents defining the most closely related inventions.
Alfred A. Hurt, MULTI-PURPOSE SQUARE, U.S. Pat. No. 4,348,815 teaches a pair of first and second elongated arms are provided and the arms include corresponding base and free ends. Pivot structure is provided and pivotably connects the base ends of the arms together for relative 360.degree. angular displacement and the pivot structure and second arm include coacting structure whereby the axis of relative pivoting of the first and second arms may be adjustably shifted along the second arm.
J. D. Murvine, STAIR GAGE, U.S. Pat. No. 1,261,596 teaches an improved gage embodying a pair of adjustably connected adjustable members through the medium of which a mechanic or carpenter may by placing the device on the stringers of the stairway and adjusting the members against the skirting boards to obtain the length and cut of both the tread and riser portions of the stairway in one operation, thus providing an improved labor saving device.
Percy H. Atherley, ROOFING SQUARE, U.S. Pat. No. 2,193,793 teaches improvements in roofing squares, and has particular reference to a device for determining the proper cutting angle for laying out rafters, stairs, hoppers and other angular cuts. The device may also be used for constructing hips or valleys as well as roof ridges.
Sidney Owen, FRAMING TOOL AND BEVEL PROTRACTOR, U.S. Pat. No. 1,616,820 teaches a framing tool, and bevel protractor, and has for its principal object to provide a structure which is efficient in enabling one to obtain the angle of bevel for each end and at the same time obtain the length of any brace, rafter, purline, beam, strut, or the like, by adjusting the tool to the actual position of the proposed brace, etc. then transferring the tool to the stick from which the brace, etc. is to be cut by placing the tool on the stick and scribing, or marking across the ends.
Joseph Liberty, GEOMETRICAL INSTRUMENT, U.S. Pat. No. 1,622,158 teaches and relates to improvements in geometrical instruments, having for an object to provide a combined straight edge, measuring device and adjustable angle, especially advantageous for use in the measuring of lumber or other material and "laying out" thereon marking indicative of the proper measurements and angles at which such material is to be cut.
David Moore, CARPENTER'S SCRIBING GAUGE, U.S. Pat. No. 1,601,138 teaches a so-called scribing gauge which consists mainly of an extensible body carrying scribing plates and protractor heads at the ends for numerous uses in carpentry, among which cutting stair threads, fitting shelves and baseboards, etc..
Oskar Schubert, JOINT MEASURING SCALE, U.S. Pat. No. 597,330 teaches joint-measuring scales of the common type which adapt the measuring scale for use as a scale for determining angles.
Merle T. Sanders, TREAD AND RISER MARKER, U.S. Pat. No. 1,563,229 teaches and relates to measuring instruments and more particularly to gages for use in determining the correct length and angle of stair treads and risers.
Frank J . Ryan, STAIR-BUILDER'S SQUARE, U.S. Pat. No. 1,489,789 teaches and relates to an improved stair builder's square of the type involving a geometrical instrument which is longitudinally adjustable and extensible and provided with opposed straight edges or blades at its ends having a sliding pivotal connection with the body of the implement.
George F. Thielman, STAIR-RULE, U.S. Pat. No. 1,349,348 teaches a rule by means of which the carpenter can easily ascertain the exact distance between the opposite faces of any portion of the stringers or rails and then placing the rule on a piece of lumber can cut it to exactly fit the space.
Uriel Sedgwick Manges, CARPENTER'S GAGE, U.S. Pat. No. 933,655 teaches and relates to carpenter's gages, the object in view being to provide a gage especially designed to enable a carpenter to obtain the correct or exact length and cut or bevel on the ends of the treads and risers of stairways, the device, embodying in connection with a main yoke, which is longitudinally extensible, end gage members which have a jointed connecting with the yoke, means for clamping and bracing the end gages relatively to the yoke for holding the several parts of the gage as a whole in fixed relation to each other after the desired adjustment has been effected.
Purley L. Reeder, COMBINED PITCH-GAGE, U.S. Pat. No. 1,269,509 teaches a new and improved carpenter's tool in the form of a gage, the principal object thereof being to enable the operator to ascertain almost instantaneously the correct angle at which a rafter used in the construction of a roof is to be cut (including the top and the base cut) and likewise the angle at which the jack rafters are to be cut; the result being accomplished by simply setting the several parts of the tool according to the rise of the rafters per foot.
Joseph B. Eliason, DISTANCE AND ANGLE MEASURING DEVICE, U.S. Pat. No. 2,647,322 teaches and relates to measuring instruments and more particularly to instruments or tools for use in measuring distances between and the relative angles of two space structural portions. It is of particular advantage in connection with various types of carpentry such as in the building of stairways, where the exact length and the angle of the ends of the treads and risers should be determined in order to make the parts fit properly. It is a tool which not only will work with accuracy but will greatly reduce the time required by the carpenter in measuring and fitting such parts.
Christ A . Christianson, STAIR SQUARE, U.S. Pat. No. 1,624,535 teaches and relates to a stair square which may be used to obtain the length, treads, and rises between the walls and stair stringers, and in building circular stairs, it may be used as a bevel square at both ends. The device is further useful in obtaining the length and miter cut of bannisters between the top and bottom rails.
Herbert C. Crawford, TREAD AND RISER GAUGE, U.S. Pat. No. 3,242,580 teaches and relates to carpenter's tools and more particularly to an improved gauge device for use in the construction of stairs, shelving and the like.
It is important to first note that none of the prior art known to the inventor hereof, teaches in any manner, the invention herein disclosed and claimed.
Clearly the instant invention provides many advantages over the prior art inventions noted above. The improved and versatile measuring device of the instant invention is capable of being used to mark-off or lay-out with consistent and repeatable accuracy pieces of work such as wooden pieces for use in construction of roofs, stairs of any form, railings and bannisters, each and any of which have uncommon relative angles or distances and is useful is scribing consistent sections for cut-out. The instant device has the capability of linear adjustments, rotational adjustments at each of the protractor ends and separate pivotal adjustment of the member connecting the protractor ends. Additionally, with the use of positionally adjustable edge-guide pins adjustable and securable within a guide slot in each of the protractor ends stops or guides may be set which provides an even further control of another dimension variable.
None of the prior art meets the objects of providing for a protractor rotatably connected at each of the ends connected by means of a central connection member which is lengthwise extendible and pivotable at a selectable pivot location. The combination of the rotatable protractor ends and the central connection member along with the positionally adjustable edge-guide pins, positionally securable within edge-guide pin guide slots in each of the protractor ends, permits a user to rapidly and easily form any ordinarily used size or angle necessary to scribe or mark off the rise and the run on the stair stringers while building stairs or for "laying out" a number of roofing rafters to be cut to fit at the ridge and onto the walls.
Various forms of squares including relatively pivotal arm portions heretofore have been provided in the art. In addition, variations of these squares are provided with spirit levels and many include structure whereby the arms may be releasably secured in adjusted angularly displaced positions.